Certain computer chip development programs, such as programs for developing processor ICs, use a combination of design methodologies. MPGZ is a semi-custom methodology used for this purpose. Application Specific Integrated Circuit (ASIC) is another methodology used in chip design, and is based on libraries of standard cells to be used in the IC design.
The functionality of the designed IC has to be tested or verified to ensure that the design performs as specified. This process of testing the functionality of the IC design is called functional verification. Typically, the functional verification process uses a simulation of the designed IC, and subjects the simulation to a battery of test cases. A test case includes instructions that cause the simulated IC to perform certain functions. For example, an instruction in a test case to write a test data pattern into a register of the simulated IC causes a write operation to be transmitted to the simulated IC, with the expected result that the test data pattern will be stored in the designated register.